This invention relates to a small-sized electronic calculator with a check function which can store and redisplay a calculating formula inputted with keys.
Heretofore, a small-sized electronic calculator with a check function, in which an inputted calculating formula is kept stored and can be read out by depressing a predetermined key, has been put into practical use. With the calculator of this type, in performing a check after inputting a calculating formula, e.g., "10+20+30=", each time the predetermined key is depressed, one pair of set number data and function data in the stored calculating formula are read out and displayed on a display portion successively as "10+", "20+", . . . , and lastly, final operation result data "60" is displayed on the display portion. There has also been put into practical use a small-sized electronic calculator with such a function that, when it becomes necessary during the check to amend (delete or insert) some data in a calculating formula, amendment data can be entered into the place of the amendment.
With such prior-art calculators, however, one pair of set number data and function data are merely indicated on the single display portion at a time. Therefore, the interim result or final result of an operation can not be replayed simultaneously with input data. Another disadvantage is that the relationship between a term being currently displayed and a term succeeding or preceding it in a calculating formula cannot be confirmed.
With the prior-art calculator which permits the amendment, when the amendment data has been inputted in order to amend a part of the calculating formula, only the amended data is indicated on the display portion. Disadvantageously, therefore, how the final result data is changed by the amendment cannot be known.
Furthermore, with the prior-art calculators, the function data is additionally indicated on a partial area of the display portion having a plurality of figure-of-eight digits. This leads to the drawback that the function display is difficult to see.
On the other hand, with small-sized electronic calculators which do not have the check function as stated above, a series of set number data and function data in a calculating formula inputted by key operations are not indicated on a display portion simultaneously with the interim result or final result of the corresponding operation. This leads to the inconvenience that the relationship between the inputted calculating formula and the operated result cannot be known.